Digital camera having a battery level check

ABSTRACT

A digital camera having a printing function which is driven by a battery comprises a printer unit operable when the voltage of the battery is equal to or higher than a first voltage, a camera unit operable when the voltage of the battery is equal to or higher than a second voltage, and a voltage detecting unit for detecting the voltage of the battery. The digital camera further comprises controller which compares the voltage of the battery detected by the voltage detecting unit with the first and second voltages and performs, based on the result of comparison, a control operation whereby the respective operations of the printer unit and the camera unit are enabled or disabled.

This application is based on application No. 11-172565 filed in Japan,the content of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to a digital camera having a printingfunction.

2. Description of the Related Art

Of devices that use batteries as power sources, such as cameras(including a silver halide camera and a digital camera), those havingbattery checking functions are prevalent. A battery checking function isa judgment of whether a battery capacitance, required to operate thedevice, is present by measuring a voltage while current, required forthe operation, flows. Since normal function/performance cannot beattained if the power-source voltage lowers, the device is soconstructed as to perform normal operations by giving a warning or thelike to the user in advance.

Conventionally, the user checks the battery, if necessary, by operatinga button provided for battery checking. As microcomputers have been usedmore widely, however, automatic battery checking has been provided.

In a camera that performs automatic battery checking, as disclosed inJapanese Unexamined Patent Publication No. HEI 5-34383, a microcomputeris so constructed as to perform battery checking when, e.g., a mainswitch is turned ON, or when a release switch is half-pressed.

On the other hand, Japanese Unexamined Patent Publication No. HEI3-29471 discloses a device comprising a digital camera integrally formedwith a printer. In a so-called mobile-type structure that performsin-situ printing of shooting data, a battery is preferably used as thepower source.

Such a digital camera with a printer requires different voltage levelsdepending on whether it is used as a camera or a printer. However,consideration has not been given to the different voltage levels in aconventional digital camera with a printer. As a matter of fact, avoltage level higher than that provided when the device is used as acamera is needed to drive the printer. In this case, however, a batterychecking level determined uniformly might lead to the situation where acamera function cannot be used (unshootable) because of a level which isusable for the function as a digital camera but lower than a batterychecking level for a printing function. There may also be the case wherebattery checking cannot be performed because of a level which isunusable for the printing function but higher than the battery checkinglevel for the digital camera.

It is therefore an object of the present invention to provide a digitalcamera having a printing function which can perform a minimum functioneven when the voltage of a power source battery is lowered.

BRIEF DESCRIPTION OF THE INVENTION SUMMARY OF THE INVENTION

The present invention may include a digital camera having a printingfunction, which is driven by a battery, said digital camera comprising:a printer unit operable when a voltage of the battery is equal to orhigher than a first voltage; a camera unit operable when the voltage ofthe battery is equal to or higher than a second voltage; a detector fordetecting the voltage of the battery; and a controller for comparing thevoltage of the battery, detected by the detector, with the first andsecond voltages and controlling respective operations of the printerunit and the camera unit based on the result of the comparison.

Thus, according to the present embodiment, the voltage judgment level isset for each of the printer unit and the camera unit. This makes itpossible to not only enable or disable the operation of each of theprinter unit and the camera unit but also enable the operation of eitherone of the printer unit and the camera unit and disable the operation ofthe other of the printer unit and the camera unit.

As a result, the minimum function can be performed even if the voltageof the power source battery is lowered.

In a further embodiment of the digital camera, the camera furthercomprises a selector for selecting either a function of the printer unitor a function of the camera unit. Preferably the controller compares avoltage required for the function selected by the selector with thevoltage of the battery. More preferably, the controller compares thevoltage of the battery with the first voltage when the printer unit isselected and the controller compares the voltage of the battery with thesecond voltage level when the camera unit is selected. Still preferablythe camera further comprises an indicator for displaying the result ofthe control operation performed by the controller whereby the respectiveoperations of the printer unit and the camera unit were enabled ordisabled. Alternatively, the controller disables or enables theoperation of either one of the printer unit selected or camera unitselected. Specifically, the controller performs the comparing operationor the control operation in synchronization with the camera unitperforming a shooting preparation operation. More specifically, thecontroller performs the comparing operation or the control operationwhen the battery is replaced.

Other objects, features, and advantages of the invention will becomeapparent from the following description and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthe specification, illustrate an embodiment of the present inventionand, together with the description, serve to explain the principles ofthe invention. In the following description, like parts are designatedby like reference numbers throughout the several drawings. In thedrawings:

FIG. 1 is a structural block diagram of a digital camera having aprinting function according to an embodiment of the present invention;

FIG. 2 is a perspective view of the camera of FIG. 1 when it is viewedfrom the front side;

FIG. 3 is a perspective view similar to FIG. 2;

FIG. 4 is a perspective view similar to FIG. 2;

FIG. 5 is a perspective view of the camera of FIG. 1 when it is viewedfrom the back side;

FIG. 6 is a detailed structural block diagram of the camera of FIG. 1;

FIG. 7 is a flow chart illustrating an operation of the camera of FIG.1;

FIG. 8 is a flow chart illustrating the operation of the camera of FIG.1;

FIG. 9 is a flow chart illustrating the operation of the camera of FIG.1;

FIG. 10 is a flow chart illustrating the operation of the camera of FIG.1;

FIG. 11 is a flow chart illustrating an interrupt process;

FIG. 12 is a flow chart illustrating the interrupt process;

FIG. 13 is a flow chart illustrating the interrupt process;

FIG. 14 is a flow chart illustrating the interrupt process;

FIG. 15 is a flow chart illustrating Exposure Control 1;

FIG. 16 is a flow chart illustrating Exposure Control 2;

FIG. 17 is a flow chart illustrating Exposure Control 2;

FIG. 18 is a perspective view of a printer unit;

FIG. 19 is a flow chart illustrating the control of the printer unit;

FIG. 20 is a flow chart illustrating battery checking;

FIGS. 21A through 21D show an exemplary display indicative of the resultof battery checking;

FIGS. 22(A) and 22(B) are an exemplary display indicative of the casewhere blurring exits;

FIG. 23 is a flow chart illustrating a shooting disable process; and

FIG. 24 is a flow chart illustrating a shooting prepare process.

DETAILED DESCRIPTION OF THE PRESENT INVENTION PREFERRED EMBODIMENTS OFTHE INVENTION

Hereinafter, embodiments of the present invention will be described withreference to the drawings.

Referring now to the drawings, a digital camera having a printingfunction according to an embodiment of the present invention will bedescribed.

FIGS. 2 to 5 are overall perspective views of the digital camera inaccordance with the present invention.

In the drawings, 1 denotes a camera main body and 2 denotes a printerunit portion internally provided with components required to perform aprinting operation, as will be described later.

The front face of the camera main body 1 is provided with: a shootinglens 3; finder window 4; an AF unit 5 for automatic focus detection(hereinafter referred to as AF); and a flash 6 which pops up from themain body. A lens barrel 30 for holding the shooting lens 3 has been soconstructed as to be extendable from and retractable into the cameramain body 1. When the lens barrel 30 has collapsed, a lens barrier 909is closed to cover the shooting lens 3.

Various operational members 7, 8, 9, 11, 12, and 13 and a displayelement 17 are disposed on the top face of the camera main body 1. Item7 denotes a release/print start switch as the operational member. Duringshooting, a switch S₁ is turned ON (start shooting preparation) when theswitch 7 is half-pressed and a switch S₂ is turned ON when the switch 7is full-pressed. During printing, the switch 7 functions as theoperational switch for starting printing. Item 8 is a mode changeoverswitch for switching among the individual modes of “OFF”, “record”,“reproduce”, and “print”. Item 9 denotes a protect switch for preventingan image once recorded from being erased by a careless operation. Item11 denotes a flash light emission mode changeover switch for switchingthe flash 6 among the individual modes of “no light emission (OFF)”,“automatic light emission (AUTO)”, and “forced light emission (ON)”.Item 12 denotes a date setting switch to be used in setting a shootingdate. Item 13 denotes a shooting mode changeover switch for changing theshooting modes of single shooting, self-timer shooting, and continuousshooting. The display element 17 is composed of, e.g., an LCD anddisplays the date, a frame number during shooting or printing, and thecontents of other set modes.

The top face of the camera main body 1 is further provided with aprinted sheet outlet 901. A printed sheet is discharged as shown in FIG.4. Item 902 denotes a sliding portion which is slidable, as shown inFIG. 3. By using an opening defined by the sliding portion 902, aninkjet cartridge 903 can be replaced. The cartridge 903 is fixed by alid portion 904. The cartridge 903 can be removed laterally from thecamera main body 1 by using fingers when the lid portion 904 is detachedupwardly. A specified number of sheets to be printed can be loaded byinsertion from the lower portion of the camera main body 1, though theyare not shown in the drawings. A detailed description will be givenlater to a printer unit 111 provided in the camera main body 1.

A memory card insertion slot 18 is provided in one side face of thecamera main body 1. A PC output terminal 19 is provided in the otherside face of the camera main body 1. The memory card insertion slot 18is an insertion slot formed to have a slit-like configuration, throughwhich an external recording medium (hereinafter referred to as a memorycard) is inserted into the camera main body 1. The PC output terminal 19is provided at an appropriate position of the side face of the cameramain body 1 to allow connection to a PC (personal computer).

As shown in FIG. 5, switches 14, 15, 910, and 908 are provided on theback face of the camera main body 1. In addition, a finder window 906, afocusing display lamp 907, and an image display LCD 905 are provided onthe back face of the camera main body 1.

The switches 14 and 15 are zoom switches. When the zoom switch 14 ispressed, the shooting lens 3 is driven toward the extreme wide-angleposition. When the zoom switch 15 is pressed, the shooting lens 3 isdriven toward the extreme telephoto position. The switches 14 and 15also serve as access switches for calling up image data recorded in amemory card 112, which will be described later. Every time the switch 14is operated, recorded images to be called up are forwardly shifted (UP).Every time the switch 15 is operated, the recorded images are backwardlyshifted (DOWN).

The switch 908 is an LCD switch for the turning ON/OFF of the imagedisplay LCD 905. The switch 910 is a camera shake correction switch forthe turning ON/OFF of a camera shake correcting operation. Duringshooting, the user can view an image to be shot through the finderwindow 906. The image display LCD 905 displays a monitored image duringshooting, while displaying a recorded image during reproduction andprinting.

The focusing display lamp 907 is lit when the shooting lens is driven toa focusing position after the switch 7 is half-pressed (the switch S₁ isturned ON) during shooting and a shooting preparing operation iscompleted. The focusing display lamp 907 flashes if a subject to be shotis at near range and therefore unshootable or if the flash is undercharging. The focusing display lamp 907 is also used in the print mode.The focusing display lamp 907 is lit when the print mode is set andflashes if an error occurs in the print mode.

FIG. 1 is a block diagram of the whole camera.

A system controller (hereinafter referred to as a CPU) 100 is forcontrolling the operation of the whole camera including a printingoperation. A subject image formed through the shooting lens 3 isinputted to a solid state image pickup device (hereinafter referred toas CCD) 101. An output image signal from the CCD 101 is processed in asignal processing unit 102, which will be described later in detail.Based on the result of distance measurement, the shooting lens 3 isdriven under the control of a lens driving unit 103 to achieve focusing.A distance measuring unit 104 obtains a distance to the subject by usinga phase difference detection system and calculates the extent to whichthe shooting lens 3 should be driven by the lens driving unit 103 basedon the distance measurement data. The lens driving unit 103 also drivesthe lens barrel 30 holding the shooting lens 3 to protrude or retractand drives the lens barrier 909 to open or close. Methods of collapsinga lens barrel by means of a lens driving unit and a mechanism foropening and closing a lens barrier by means of a lens driving unit arewell known, such as is described in U.S. Pat. No. 5,489,958 to Moriya etal. A light measuring unit 105 measures the luminance of the subject andoutputs light measurement data to the CPU 100. An exposure control unit106 receives, from the CPU 100, data on an exposure time (shutter speed)Tv and a f/number Av obtained based on the result of light measurementto control exposure. A display unit 107 is composed of the displayelement 17, the LCD 905, and a portion for driving the display element17 and the LCD 905.

A camera shake detector 400 detects the amount of camera shake duringshooting by means of an acceleration sensor provided within the cameramain body 1. Based on the result of detecting camera shake from thecamera shake detector 400, a camera shake correcting unit 402 correctsthe camera shake. Specifically, the camera shake correcting unit 402corrects the camera shake by driving a correcting optical member in ashooting optical system in a direction perpendicular to an optical axisby using an actuator. An image processing unit 300 processes an imagesignal and, if necessary, processes an image such that it is outputtedto the image display LCD 905 and to the printer unit 111.

A flash unit 108 is controlled by a voltage increase control signal forcharging and a light emission control signal, which are outputted fromthe CPU 100, and causes the flash 6 to emit light. The flash unit 108also drives the flash to an in-use position (pop up) or to an out-of-useposition (pop down) based on a control signal from the CPU 100.Mechanisms for driving a flash to the in-use position and to theout-of-use position are well known, such as is described in U.S. Pat.No. 5,625,852 to Wada et al.

A power source unit 109 supplies electric power at a predetermined highvoltage to the CCD 101 and supplies electric power at a predeterminedvoltage to the CPU 100 and to the other circuit components. A batterycheck circuit 110 is connected to a power source battery within thepower source unit 109 and detects the capacitance of the power sourcebattery. The result of detection is outputted to the CPU 100.

The printer unit 111 is driven under the control of the CPU 100 to printout the image signal onto a recording sheet, which will be describedlater in detail. The memory card 112 is a recording medium detachablefrom the camera main body 1, which is composed of, e.g., a SRAM in whichplural frames of images can be recorded. An external output interface(I/F) 19 corresponds to the PC output terminal of FIG. 2.

Next, a description will be given to switches S_(OFF) to S_(E).

The switch S_(OFF) is turned ON when the mode changeover switch 8 is inthe “OFF” position to disable the operation of the camera.

The switch S_(REC) is turned ON when the mode changeover switch 8 is inthe “record” position to enable the camera to shoot.

The switch S_(REP) is turned ON when the mode changeover switch 8 is inthe “reproduce” position to enable the transfer of an image to the PC orthe like.

The switch S_(PRT) is turned ON when the mode changeover switch 8 is inthe “uprint” position to enable the printing out of the recorded image.

The switch S₁ is turned ON through single pressing (half-pressing) ofthe release/print start switch 7 during shooting and gives aninstruction to start shooting preparation.

The switch S₂ is turned ON through double pressing (full-pressing) ofthe release/print start switch 7 during shooting and gives aninstruction to shoot. In the print mode, the switch S₂ gives aninstruction to start printing.

The switch S_(UP) is turned ON every time the switch 14 is pressed.During shooting, the switch S_(UP) drives the shooting lens toward theextreme telephoto position. During reproduction, the switch S_(UP)effects forward reproduction of recorded images.

The switch S_(DOWN) is turned ON every time the switch 15 is pressed.During shooting, the switch S_(DOWN) drives the shooting lens toward theextreme wide-angle position. During reproduction, the switch S_(DOWN)effects backward reproduction of the recorded images.

The switch S_(PRO) alternately protects the recorded images and cancelsthe protection every time the protect switch 9 is pressed.

The switch S_(VI) detects the ON/OFF state of the camera shakecorrection switch 910.

The switch S_(LCD) detects the ON/OFF state of the LCD switch 908.

The switch S_(CARD) is turned ON when the memory card 112 is inserted.

The switch S_(FL) is turned ON every time the flash light emission modechangeover switch 11 is pressed to cyclically switch the flash among theindividual modes of no light emission, automatic light emission, andforced light emission.

The switch S_(ADJ) corresponds to the date setting switch 12.

The switch S_(MODE) is turned ON every time the shooting mode changeoverswitch 13 is pressed to cyclically change the shooting mode among singleshooting, self-timer shooting, and continuous shooting.

The switch S_(E) detects the ON/OFF state of an erase switch not shown.

FIG. 6 is a detailed block diagram showing the control system of animage pickup unit (the portion enclosed in the dotted rectangle in FIG.1).

In FIG. 6, the CCD 101 is constructed as a color area sensor whichphotoelectrically converts an optical image of the subject formed by alens 301 and a relay lens 302 to an image signal having R (red), G(green), and B (blue) color components (signal composed of a sequence ofimage signals received at individual pixels) and outputs the imagesignal.

A timing generator 201 generates a drive control signal to the CCD 101based on a reference clock transmitted from a timing control circuit202. The timing generator 201 generates clock signals such as a timingsignal for the initiation/completion of integration(initiation/completion of exposure) and readout control signals for areceived light signal from each pixel (such as a horizontal synchronizesignal, a vertical synchronize signal, and a transfer signal) andoutputs the individual signals to the CCD 101.

A signal processing circuit 213 performs specified analog signalprocessing with respect to an image signal (analog signal) outputtedfrom the CCD 101. The signal processing circuit 213 has a CDS(correlated double sampling) circuit and an AGC (autogain control)circuit. The signal processing circuit 213 reduces the noise of theimage signal by using the CDS circuit and adjusts the level of the imagesignal by adjusting the gain of the AGC circuit.

An A/D converter 205 converts each of the pixel signals of the imagesignal to a 10-bit digital signal. The A/D converter 205 converts eachof the pixel signals (analog signals) to a 10-bit digital signal basedon an A/D conversion clock from the timing control circuit 202.

A black level correcting circuit 206 corrects the black level of thepixel signal after A/D conversion (hereinafter referred to as pixeldata) to a standard level. A WB (white balance) circuit 207 performslevel conversion with respect to pixel data on each of the R, G, and Bcolor components such that white balance is also automatically adjustedafter γ correction. The WB circuit 207 corrects the level of pixel dataon each of the R, G, and B color components by using a level conversiontable within the overall control unit 100, i.e., the CPU 100. Conversioncoefficients for the individual color components in the level conversiontable (the inclinations of the characteristics) are set by the overallcontrol unit 100 for each shot image.

A γ correcting circuit 208 corrects the γ characteristic of the pixeldata. The γ correcting circuit 208 has, e.g., six γ correction tableswith different γ characteristics to perform γ correction of the pixeldata based on that one of the γ correction tables specified according toa scene to be shot and shooting conditions.

An image memory 209 is for storing the pixel data outputted from the γcorrecting circuit 208. The image memory 209 has a storage capacity forone frame. If the CCD 101 has pixels in n columns and m rows, therefore,the image memory 209 has a capacity for storing data on n×m pixels suchthat each pixel data is stored at the corresponding pixel location.

In a shooting standby state, each pixel data on an image picked up byCCD 101 every {fraction (1/30)} seconds is subjected to specified signalprocessing performed by the A/D converter 205 to the γ correctingcircuit 208. The pixel data after signal processing is stored in theimage memory 209 and displayed on the image display LCD 905 via theoverall control unit 100. The photographer can visually recognize theoptical image of the subject by the image displayed on the image displayLCD 905. In the reproduction mode, the image read from the memory card112 is subjected to specified signal processing performed in the imageprocessing unit 300 via the overall control unit 100 and thenreproductively displayed on the LCD display unit 905.

An aperture control driver 204 adjusts the f/number of an apertureprovided in the lens 302 to a set value. An AF actuator 215 drives thelens 302 to a focusing position.

If the release/print start switch 7 is operated in the shooting mode togive an instruction to shoot, the overall control unit 100 generates athumbnail image of the image inputted to the image memory 209 and animage compressed with a compressibility K set by using a compressibilitysetting switch (also used as the date setting switch 12) in accordancewith the JPEG method. The two images are recorded on the memory card 112along with tag data (data such as frame number, exposure value, shutterspeed, compressibility K, shooting date, scene data, and the result ofimage judgment) on the shot image.

For example, 230 frames of images can be stored in the memory card 112if the capacity of the memory card 112 is 64 MB and the compressibilityK is {fraction (1/20)}. For each frame, a tag portion, high-resolutionimage data compressed in accordance with the JPEG method (1600×1200pixels), and image data for thumbnail display (160×120 pixels) arerecorded. It is possible to regard the image data as, e.g., an imagefile in the form of an EXIF on a frame-by-frame basis.

Next, a description will be given to the construction of the printerunit 111 with reference to FIG. 18.

In a lower part of the housing of the camera main body 1, there areprovided a guide shaft 2′ and a lead screw 3′ extending in parallel witheach other. Between the guide shaft 2′ and the lead screw 3′, arecording head 5′ (not shown) composed of an inkjet head cartridge issupported movably via a carriage 4′. The recording head 5′ has heads forfour colors of Y (Yellow), M (Magenta), C (Cyan), and K (Black) to allowfull-color printing. The lead screw 3′ is engaged with a drive motor 6′rotatable in forward and reverse directions via gears 7′ and 8′. Byrotating the lead screw 3′ forwardly and reversely by means of the drivemotor 6′, the recording head 5′ is moved in the directions indicated bythe arrows a and b along the guide shaft 2′.

A paper pressing plate 9′ and a platen 10′ in the form of a roller areprovided posterior to the lead screw 3′. A sheet 11′ to be printed issupplied while it is pressed by the paper pressing plate 9′ onto theplaten 10′.The carriage 4′ is provided with a lever 4 a′ protrudingtherefrom. Detecting means 12′ composed of a photocoupler provided inthe home position of the carriage 4′ detects the lever 4 a′ to controlthe direction of rotation of the drive motor 6′.

Item 13′ denotes a support member for supporting a cap member 14′ withwhich the front face of the recording head 5′ is capped. Item 15′denotes sucking means for sucking air from inside the cap member 14′,which recovers the recording head 5′ by suction via an opening 16′ inthe cap member 14′. Item 17′ denotes a cleaning blade. Item 18′ denotesa member for rendering the cleaning blade 17′ movable in the forward andbackward directions, which is supported by a main body support plate19′. Item 20′ denotes a lever for initiating suction for recovery, whichmoves with the movement of a cam 21′ engaged with the carriage 4′. Themovement of the lever 20′ is controlled by switching the driving forceof the drive motor 6′ by using well-known changeover means such as aclutch.

The digital camera has been constructed such that, of the capping by thecap member 14′, the cleaning by the cleaning blade 17′, and the suctionrecovery by the lever 20′, a desired operation is performed by theaction of the lead screw 3′ when the carriage 4′ is positioned in thehome position area. The desired operation may also be controlled withwell-known timing.

Although a well-known system using a piezoelectric element has been usedas the inkjet printer in the present embodiment, it is not limitedthereto. An inkjet printer in a so-called bubblejet system provided withan electrothermal converting element may also be used instead.

Next, a description will be given to the operation of the digital cameraof the present embodiment.

The operation of the camera is controlled by the CPU 100 in accordancewith a program in a ROM (not shown) connected to the CPU 100.

FIGS. 7 to 10 are main flow charts illustrating the operation of thecamera.

As shown in FIG. 7, the power-source battery is attached to thepower-source unit 109 to supply electric power to the CPU 100 andthereby initiate the operation. First, battery checking is performed(step #99).

Battery checking is performed in accordance with the flow chart shown inFIG. 20.

First, the voltage V₁, at the power-source battery of the power-sourceunit 109 is measured by the battery checking circuit 110 (step #610).The CPU 100 compares the magnitude of the voltage V₁, with those ofthree reference voltages V_(S), V_(P), and V_(C) (steps #620, #630, and#640). Based on the result of comparison, the displays 500 of FIG. 21Ato 21D are shown on the display 17 (steps #622, #632, #642, and #650).Here, V_(S)>V_(P)>V_(C) are satisfied.

If V₁≧V_(S) is satisfied (NO in step #620), each of the printer andcamera is usable so that the printer mark 504 and the camera mark 506are illuminated, as shown in FIG. 21A (step #622).

If V_(S)>V₁≧V_(P) are satisfied (YES in step #620 and NO in step #630),each of the printer and the camera is usable but the power remaining inthe power-source battery is low, so that the printer mark 504 and thecamera mark 506 flash, as shown in FIG. 21B (step #632). IfV_(P)>V₁≧V_(C) are satisfied (YES in step #620, YES in step #630, and NOin step #640), the printer is unusable but the camera is usable so thatthe cross mark x is displayed in overlapping relation to the printermark 504 and the camera mark 500 flashes, as shown in FIG. 21C (step#642). In addition, the operation of the printer unit 111 is disabled(step #644). Then, it is determined whether or not the print mode isestablished (step #646) and if the print mode is not established (NO instep #646), process flow returns. If the print mode is established (YESin step #644), the flow returns to “START” in FIG. 7 where thereattachment of the power source is awaited.

If V_(C) >V₁ is satisfied (YES in step #620, YES in step #630, and YESin step #640), each of the printer and camera is unusable so that thecross mark x is displayed in overlapping relation to each of the printermark 504 and the camera mark 506, as shown in FIG. 21D (step #642).Then, the operation of the whole camera is disabled (step #652) and theflow returns to “START” in FIG. 7 where the reattachment of the powersource is awaited.

It is to be noted that battery checking is performed appropriately inaccordance with the flow similar to the foregoing, in addition to thatperformed in step #99 of FIG. 7.

Back to FIG. 7, it is judged whether or not the main switch SM has beenturned ON (step #100) subsequently to the battery checking (step #99).The main switch SM is OFF when the mode changeover switch 8 is in the“OFF” mode position (i.e., when the switch S_(OFF) is ON). In the othercases, i.e., if the mode changeover switch 8 is in any of the “record”,“reproduce”, and “print” mode positions (i.e., when the switch S_(OFF)is OFF), the main switch SM is ON.

If the main switch SM is OFF (NO in step #100), an interrupt (INT),which will be described later, is disabled (step #101) so that a flag isreset (step #102). Then, if some indication is shown on the display 17,the indication is dismissed (step #103) and a shooting disable processis performed (step #103 a). The flow returns again to step #100 wherethe turning ON of the main switch SM is awaited.

The shooting disable process is performed in accordance with the flowchart shown in FIG. 23.

First, the flash 6 is lowered from the pop up position (in-use position)shown in FIG. 2 to the pop down position (out-of-use position) shown inFIGS. 3 to 5 (step #700). Next, the lens barrel 30 is collapsed (step#702) and the lens barrier 909 is closed (step #704). Thereafter, it isdetermined whether or not the camera shake correction switch 910 is ON.If the camera shake correction switch 910 is ON (YES in step #706),power supply to the camera shake correcting unit 402 and to the camerashake detecting unit 400 is turned OFF (step #708, step #710) and theflow returns. If the camera shake correction switch 910 is OFF (NO instep #706), step #708 and step #710 are not performed and the flowreturns.

Back to FIG. 7, if the main switch SM is ON (YES in step #100), thebattery checking as described above is performed (step #100 a) and ashooting prepare process is performed (step #100 b).

The shooting prepare process is performed in accordance with the flowchart shown in FIG. 24.

First, the lens barrier 909 is opened (step #800) and the lens barrel 30is protruded to the initial position (step #802). Next, the flash 6 ispopped up (step #804) and it is examined whether or not the camera shakecorrection switch is ON (step #806). If the camera shake correctionswitch 910 is ON (YES in step #806), power supply to the camera shakecorrecting unit 402 and to the camera shake detecting unit 400 is turnedON (YES in step #808 and step #810) and the flow returns. If the camerashake correction switch 910 is OFF (NO in step #806), steps #808 and#810 are not performed and the flow returns.

Back to FIG. 7, an interrupt (INT) is enabled (step #104) after thecompletion of the shooting prepare process (step #100 b) and the ON/OFFstate of the LCD switch 908 is examined (step #104).

If the LCD switch 908 is OFF (NO in step #104 a), it is examined whetheror not the image display LCD 905 is ON, i.e., illuminated (step #104 b).If the image display LCD 905 is OFF, i.e., unilluminated (NO in step#104 b), the flow proceeds to step #105. If the image display LCD 905 isON (YES in step #104 b), power supply to the CCD 101 is halted (step#104 c) and the image display LCD 905 is turned OFF (step #104 d).Thereafter, the flow proceeds to step #105.

If the LCD switch 908 is ON (YES in step #104 a), electric power issupplied to the CCD 101 (step #104 e) and the image display LCD 905 isturned ON (step #104 f). Thereafter, the flow proceeds to step #105.

In step #105, it is judged whether or not the release/print start switch7 has shifted from the OFF state to the ON state by single pressing,i.e., whether or not the switch S₁ is ON. If the switch S₁ is not ON (NOin step #105), the flow returns to step #100 to repeat the foregoingroutine from step #100 to step #105. If the switch S₁ is ON (YES in step#105), on the other hand, the flow proceeds to FIG. 8. In FIG. 8, thebattery checking as described above is performed (step #105 a) and thenpower is supplied to the CCD 101 if the power supply to the CCD 101 isnot ON (step #105 b, step #105 c).

When power supply to the CCD 101 is initiated, the power source unit 109supplies, in response to a signal from the CPU 100 shown in FIG. 1, ahigh voltage VH as a drive voltage to the CCD 101. Simultaneously withthe initiation of power supply, an instruction signal for theinitialization of the CCD 101 is outputted to the timing generator 201so that the charge remaining in the CCD 101 is released.

Next, the distance measuring unit 104 performs distance measurement(step #105 e) and it is judged whether or not the subject is at nearrange (step #105 f).

If the subject is at near range (YES in step #105 f), the focusingdisplay lamp 907 flashes (step #105 h) and the turning ON of the switchS₂ is disabled (step #105 i). Thereafter, the turning OFF of the switchS₁ is awaited (step #105 j) and, if the switch S₁ is turned OFF (NO instep #105 j), the focusing display lamp 907 is extinguished (step #105k) and the flow returns to step #100.

If the subject is not at near range (NO in step #105 f), the shootinglens 3 is driven to the focusing position (step #105 g). Subsequently,the light measuring unit 105 performs light measurement and the exposuretime Tv and the f/number Av are calculated (step #108). From the resultof light measurement, it is judged whether or not the luminance of thesubject is low (step #109).

If the luminance of the subject is judged to be low (YES in step #109),the light emission timing for the flash 6 is calculated based on themeasured light values (step #111) so that flash shooting is performed,as shown in FIG. 9. Next, it is judged whether or not charge requiredfor light emission has already been accumulated in a capacitor forcharge accumulation within the flash unit 108 (step #112). If theaccumulation of charge has not been completed (NO in step #112), anundercharge flag is set to “1” and charging is initiated (step #113,step #114) and the focusing display lamp 907 flashes (114 a), so thatthe flow returns to step #112 to await the completion of charging.

When the charging of the capacitor for charge accumulation is completed(YES in step #112), the focusing display lamp 907 is extinguished if itis flashing (step #112 a, step #112 b) and the flow proceeds to step#115. In step #115, charging is halted and it is judged in step #116whether or not the undercharge flag is “1”.

If the undercharge flag is “1” (YES in step #116), the undercharge flagis set tb “0” in step #117 and the subsequent turning OFF of the switchS₁ is awaited (step #118). If the switch S₁ is turned OFF (YES in step#118), the flow returns to step #100 and the camera is brought into aso-called release locked state.

If the undercharge flag is “0” in step #116 (NO in step #116), on theother hand, the flow proceeds to step #119 where the subroutine forExposure Control 2 is executed. After that, the flow proceeds to step#120 in FIG. 8.

The subroutine for Exposure Control 2 is executed in accordance with theflow charts shown in FIGS 16 and 17.

First, an interrupt (INT) is disabled (step #401) and the focusingdisplay lamp 907 is lit (step #401 a). Thereafter, it is judged whetheror not the switch S₂ is ON (step #401 b).

If the switch S₂ is OFF (NO in step #401 b) and the switch S₁ is ON (YESin step #401 d), the flow returns to step #401. If the switch S₂ is OFF(NO in step #401 b) and the switch S₁ is OFF (NO in step #401 d), theflow proceeds to step #100 in FIG. 7.

When the switch S₂ is ON (YES in step #401 b), if display on the LCD 905is ON, an image to be displayed on the image display LCD 905 is locked,i.e., fixed and the same image is displayed (step #401 x). Next, thecamera shake detecting unit 400 detects the amount of camera shake (step#401 c) and the CPU 100 outputs the exposure time Tv and f/number Avcalculated based on the result of light measurement to the exposurecontrol unit 106 (step #402). The exposure control unit 106 drives theaperture of the camera main body 1 based on the data and outputs ashutter control signal to the timing generator 201 depending on theexposure time Tv to perform exposure of the CCD 101. Upon receipt of thesignal indicative of the initiation of exposure from the exposurecontrol unit 106 (step #403), the CPU 100 starts a timer within the CPU100 based on the timing for flash light emission obtained in step #111(step #404). The emission of light from the flash 6 is timed after agiven time has elapsed from the initiation of the exposure of the CCD101.

Next, as shown in FIG. 17, the CPU 100 judges whether or not an exposurecomplete signal has been inputted thereto from the exposure control unit106 (step #405). The reason for the judgment is that the exposure timeTv is an expected value and the exposure control unit 106 may output anexposure complete signal even before the time for flash light emissioncomes if the luminance of the subject is increased abruptly during,e.g., the counting operation of the timer for flash light emission.

That is, if the exposure control unit 106 outputs an exposure completesignal before the time for flash light emission comes (YES in step#405), the flow proceeds to step #408 a so that the exposing operationis completed without causing the flash 6 to emit light.

If the time for flash light emission has come before the completion ofexposure (NO in step #405 and YES in step #406), the CPU 100 causes theflash 6 to emit light. Thereafter, an exposure complete signal isoutputted to the exposure control unit 106 (step #407, step #408) andthe flow proceeds to step #408 a so that a the exposing operation iscompleted.

In step #408 a, the focusing display lamp 907 is extinguished. Next,image display on the image display LCD 905 is unlocked and the shotimage from the CCD 101 is monitor-displayed (step #408 b). Then, it isjudged whether or not the amount of camera shake during exposure is overa predetermined value (step #408 c). The predetermined value is, e.g.,within the range within which camera shake can be corrected by thecamera shake correcting unit 402. If the amount of camera shake is notover the predetermined value (NO in step #408 c), only the image signalreceived from the CCD 101 is written in the image memory 209 of thecamera main body 1 (step #409). If the amount of camera shake is overthe predetermined value (YES in step #408 c), camera shake data is addedto the image signal from the CCD 101, which is written in the imagememory 209 (step #408 d, step #409). Although the present embodiment hasadded the data only when the amount of camera shake is maximum (when theamount of camera shake detected by the camera shake detecting unit 400is over the camera shake correctable range), the amount of camera shakemay also be recorded constantly. At the completion of the foregoingprocess, an interrupt (INT) is enabled in step #410.

On the other hand, if it is judged as a result of light measurement thatthe luminance of the subject is not low in step #109 of FIG. 8 (NO instep #109), the subroutine for Exposure Control 1 not involving flashlight emission is executed (step #110).

The subroutine for Exposure Control 1 is executed in accordance with theflow chart shown in FIG. 15.

First, an interrupt (INT) is disabled in step #301 and the focusingdisplay lamp 907 is lit (step #301 a). Thereafter, it is judged whetheror not the switch S₂ is ON (step#301 b).

If the switch S₂ is OFF (NO in step #301 b) and the switch S₁ is ON (YESin step #301 d), the flow proceeds to step #301 b. If the switch S₂ isOFF (NO in step #301 b) and the switch S₁ is OFF (NO in step #301 d),the flow proceeds to step #100 in FIG. 7.

If the switch S₂ is ON (YES in step #301 b) and display on the LCD 905is ON, an image to be displayed on the image display LCD 905 is locked,i.e., fixed and the same image is displayed (step #301 x). Next, thecamera shake detecting unit 400 detects the amount of camera shake (step#301 c) and the CPU 100 outputs the exposure time Tv and f/number Avcalculated based on the result of light measurement to the exposurecontrol unit 106 (step #302). The exposure control unit 106 drives theaperture of the camera main body 1 based on the data and outputs ashutter control signal to the timing generator 201 depending on theexposure time Tv to perform exposure of the CCD 101. Upon receipt of thesignal indicative of the initiation of exposure from the exposurecontrol unit 106 (step #303), the CPU 100 judges whether or not anexposure complete signal has been outputted from the exposure controlunit 106 (step #305). If the exposure time Tv is up, the exposurecontrol unit 106 outputs an exposure complete signal to the CPU 100 (YESin step #305) to complete the exposing operation.

When the exposing operation is completed, the focusing display lamp 907is extinguished (step #305 a) and image display on the image display LCD905 is unlocked (step #305 b), similarly to the process performed insteps #408 a to #410 in the routine for Exposure Control 2. Further, theimage signal inputted to the CCD 101 is written in the image memory 209of the camera main body 1, while the amount of camera shake during theexposing operation is compared with a predetermined value (step #305 c).The predetermined value may be the same as or different from the valueused in the case of Exposure Control 2 described above, since shootingdoes not involve flash light emission. If the amount of camera shake isover the predetermined value (YES in step #305 c), camera shake data isadded to the image signal, which is written in the image memory 209(step #305 d, step #308). At the completion of the foregoing process,the CPU 100 enables an interrupt (INT) in step #309 and completes theexposure control operation.

After the foregoing operations of Exposure Control 1 and ExposureControl 2 are completed, the image signal and camera shake data storedin the image memory 209 is transferred to the memory card 112.

When the subroutines for exposure control in step #110 of FIG. 8 or instep #119 of FIG. 9 are completed, the frame number is updated only by 1in step #120 of FIG. 8 so that the updated frame number is displayed onthe display 17. Next, when the shooting of all the frames is completedand shooting for all the frames within the memory card 112 is completed(YES in step #121), a warning is given on display or by audio in step#122 to draw the photographer's attention. If recording is possible, awarning is not given.

In step #123 of FIG. 10, the CPU 100 awaits the turning OFF of theswitch S₁ and, if the switch S₁ is turned OFF (YES in step #123), theCPU 100 outputs a signal to turn OFF power supply to the CCD 101 andcompletes shooting for one frame (step #124).

After the foregoing process, it is judged whether or not the charging ofthe flash 6 has been completed (step #125). If the charging has not beencompleted (NO in step #125), the undercharge flag is set to “1” and thecharging is initiated (step #126, step #127). If the charging has beencompleted (YES in step #125), the undercharge flag is set to “0” and thecharging is halted (step #128, step #129). The flow then returns to step#100 of FIG. 7 and the operations of steps #100 to #129 are repeated.

Next, a description will be given to the process performed if aninterrupt (INT) occurs after step #104 where the interrupt (INT) isenabled with reference to the flow charts of FIGS. 11 to 14. Theinterrupt (INT) occurs when the mode changeover switch 8 is in the“print” mode position for giving an instruction to print or in the“reproduce” mode position for giving an instruction to reproduce, i.e.,when the switch S_(PRT) or S_(REP) is ON. The interrupt (INT) alsooccurs when the switches 14 and 15 are operated.

When the interrupt (INT) occurs, it is judged in step #201 whether ornot the undercharge flag is “1”. If the undercharge flag is “1”, thecharging is temporarily halted in step #202 by judging that theinterrupt has occurred during the charging of the capacitor for chargeaccumulation. If the undercharge flag is “0”, step #202 is skipped andit is judged in step #203 whether or not the switch S_(PRT) is ON. Ifthe switch S_(PRT) is ON (YES in step #203), it is judged that the flowhas moved to the printing operation. Subsequently, the foregoing batterychecking and shooting disable process are performed (step #203 a, step#203 b) and the flow proceeds to step #204. If the switch S_(PRT) is OFF(NO in step #203), on the other hand, the flow proceeds to step #223.

In step #204, indication of the print mode is shown on the display 17and then it is judged whether or not the switch 14 has shifted from theOFF state to the ON state, i.e., whether or not the switch 14 has beenpressed (step #205). If the switch 14 has been ON (YES in step #205),the flow proceeds to step #206. If the switch 14 remains in the OFF orON state or is brought from the ON state to the OFF state (NO in step#205), the flow proceeds to step #210.

In step #206, the CPU 100 judges that the switch 14 has been pressed,updates the frame number only by 1, and displays the updated framenumber on the display 17. An address controller (not shown) furtheroutputs address data corresponding to the frame number to reproduce animage corresponding to the frame number (step #207). After a waitoperation is performed for the foregoing process in step #208, imagedata corresponding to the current frame number is displayed on the imagedisplay LCD 905 (step #209). Then, the presence or absence of camerashake is determined based on camera shake data corresponding to thedisplayed image (step #209 a). If there is no camera shake data (NO instep #209 a), the flow returns directly to step #205. If there is camerashake data (YES in step #209 a), a camera shake mark 602 is illuminatedas shown in FIG. 22(A) to indicate in an image display 600 that thedisplayed image has camera shake data (step #209′), so that the flowreturns to step #205. This increments the frame number by 1 every timethe switch 14 is turned ON, so that the process of monitor-displayingthe image corresponding to the frame number on the image display LCD 905is repeated.

On the other hand, it is judged in step #210 whether or not the switch14 is ON. If the switch 14 is ON (YES in step S210), the flow returns tostep #205. If the switch 14 is OFF (NO in step #210), the flow moves tostep #211 of FIG. 12.

Next, when the switch 15 is turned ON successively to the switch 14 inFIG. 12 (YES in step #211), the flow moves to step #212. If the switch15 remains in the OFF or ON state or is brought from the ON state to theOFF state (NO in step #211), the flow moves to step #216.

In step #212, the CPU 100 judges that the switch 15 has been pressed todecrement the frame number only by one and display the decremented framenumber on the display 17. The address controller further outputs addressdata corresponding to the frame number to reproduce an imagecorresponding to the frame number (step #213). After a wait operation isperformed for processing in step #214, image data corresponding to thecurrent frame number is displayed on the image display LCD 905 (step#215). Then, it is judged, based on camera shake data corresponding tothe displayed image, whether or not the image in the frame has camerashake data (step #215 a). If there is no camera shake data, the processreturns directly to step #211. If there is camera shake data, the camerashake mark 602 is illuminated to indicate that the image displayed onthe monitor image display 600 has the camera shake data, similar to step#209′ (step #215 b) and the flow returns to step #211. As a result, theprocess of decrementing the frame number by 1 every time the switch 15is turned ON and displaying the image corresponding to the frame numberon the image display LCD 905 is repeated.

In step #216, on the other hand, it is judged whether or not the switch15 is ON. If the switch 15 is ON (YES in step #216), the flow returns tostep #211. If the switch 15 is OFF (NO in step #216), the flow moves tostep #250.

In step #250, it is judged whether or not the erase switch S_(E) hasbeen turned ON. If the erase switch S_(E) has been turned ON (YES instep #250), the image displayed on the image display LCD 905 is erased(step #251) and the flow moves to step #203 of FIG. 11. If the eraseswitch S_(E) has not been turned ON (NO in step #250), on the otherhand, the flow moves to step #217 where it is judged whether or not theswitch S₂ has been turned ON.

If the switch S₂ has not been turned ON (NO in step #217), the CPU 100judges that printing should not be performed so that the flow returns tostep #203 of FIG. 11 to repeat the foregoing process. If the switch S₂has been turned ON (YES in step #217), the presence or absence of camerashake data in the displayed image is determined (step #217 a). If thereis no camera shake data (NO in step #217 a), the flow proceeds to step#218. If there is camera shake data (YES in step #217 a), the camerashake indication 602 is displayed flashing to give a warning that theframe to be printed has camera shake data (step #207′). The flowproceeds to step #218 if the switch S₂ is turned ON again within aspecified time after the warning. If the switch S₂ is not turned ONwithin the specified time after the warning, the flow proceeds to step#203 (step #217 c, step #217 d).

In step #218, the CPU 100 outputs a print instruction signal to theimage processing unit 300 so that the flow moves to the printingoperation. Upon receipt of the signal, the image processing unit 300initiates signal processing for the printing operation. The CPU 100displays that printing is currently performed on the display 17 (step#219), while controlling the printing operation (step #220).

The control of the printing operation is executed in accordance with thesequence shown in FIG. 19.

That is, the CPU 100 instructs a sheet, that is to be printed, to besupplied to the printing position (step #510). Then, at the homeposition of the recording head 5′, preparatory discharge is performed toensure the printing operation (step #520). The preparatory discharge isfor eliminating the clogging of the recording head 5′. The preparatorydischarge is also for recovering, e.g., the nozzle having degradedperformance due to, e.g., the pigment of ink from which moisture hasevaporated.

Next, the CPU 100 initiates the printing operation (step #530). That is,the focusing display lamp 907 is lit (step #531) and image data isimage-processed to be outputted from the printer and then printed out ofthe printer unit 111 (step #532). During printing (NO in step #533), theoccurrence of an error is monitored (step #534). If an error is detected(YES in step #534), the printing out is interrupted and the display lamp907 flashes (step #535). If the error is removed (YES in step #534), theflow proceeds to step #535 so that the printing operation is continued.If the error is not removed (NO in step #536), the turning OFF of theswitch S_(PRT) is awaited (step #537). When the switch S_(PRT) is turnedOFF, the CPU 100 halts printing (step #538) and the focusing displaylamp 907 is extinguished so that the flow returns to step #100 of FIG.7.

When the specified printing operation is completed (YES in step #533),the sheet 11′ printed in the printer unit 111 is transported from theoutlet 901 of the camera main body 1 to the position where the printedsheet 11′ is prevented from falling (step #540). Thereafter, thefocusing display lamp 907 is extinguished (step #942) and the userrecognizes the completion of the printing operation. Next, the CPU 100transmits a print complete signal and returns the carriage 4′ to thehome position so that cleaning operation is performed (step #550).

The preparatory discharge and the cleaning operation are performed torender recording more effective in a printer in an inkjet printingsystem, whereby the recording head 5′ is cleaned with cleaning meanssuch as a suction pump, a cleaning blade, or the like.

The printing is completed in step #221 of FIG. 12. If a print completesignal has been outputted (YES in step #221), the CPU 100 displays thecompletion of the printing on the display 17 (step #222). By theforegoing operations, the printing for one frame is completed so thatthe flow returns to step #203 of FIG. 11.

If the turning ON of the switch S_(PRT) has not been detected in step#203 of FIG. 11 (NO in step #203), on the other hand, the CPU 100 doesnot perform the printing operation but performs the operations of thesteps subsequent to step #223. In step #223, it is judged whether or notthe reproduction switch S_(REP) has been turned ON. If the reproductionswitch S_(REP) is OFF (NO in step #223), the CPU 100 does not performreproductive display on the image display LCD 905 and moves to step #235of FIG. 14. If the reproduction switch S_(REP) is ON (YES in step #223),on the other hand, the foregoing battery checking is performed (step#223 a) so that the foregoing shooting disable process is performed(step #223 b). Thereafter, the reproduce mode is displayed on thedisplay 17 to indicate that reproduction will be performed on the imagereproduction LCD 905 (step #224).

In the reproduction mode, it is subsequently judged whether the switch14 or 15 has been turned ON (step #225, step #230).

If the switch 14 remains in the OFF or ON state or is brought from theON state to the OFF state (NO in step #225), the flow moves to step#229. If the switch 14 is turned ON (YES in step #225), on the otherhand, the frame number is incremented only by 1 and the updated framenumber is displayed, while the address controller outputs address datacorresponding to the current frame number to reproduce an imagecorresponding to the frame number (step #226, step #227). Subsequently,image data corresponding to the current frame number is displayed (step#228), as described above. Then, the flow returns to step #225 and theprocess of incrementing the frame number by 1 every time the switch 14is turned ON and displaying the image corresponding to the frame numberon the image display LCD 905 is repeated.

In step #229, on the other hand, it is judged whether or not the switch14 is ON. If the switch 14 is ON (YES in step #229), the flow returns tostep #225. If the switch 14 is OFF (NO in step #229), the flow moves tostep #230.

Next, if the switch 15 is turned ON successively to the switch 14 (YESin step #230), the flow moves to step #231. On the other hand, if theswitch 15 remains in the OFF or ON state or brought from the ON state tothe OFF state (NO in step #230), the flow moves to step #234.

In step #231, the frame number is decremented only by 1 and displayed byjudging that the switch 15 has been pressed, while the addresscontroller outputs address data corresponding to the frame number toreproduce an image corresponding to the frame number (step #231, step#232). Subsequently, image data corresponding to the current framenumber is displayed (step #233), as described above. Then, the flowreturns to step #230 and the process of decrementing the frame number by1 every time the switch 15 is turned ON and displaying the imagecorresponding the frame number is repeated.

In step #234, on the other hand, it is judged whether or not the switch15 is ON. If the switch 15 is ON (YES in step #234), the flow returns tostep #230. If the switch 15 is OFF (NO in step #234), the flow proceedsto step #252.

In step #252, it is judged whether or not the erase switch S_(E) hasbeen turned ON. If the erase switch S_(E) has been turned ON (YES instep #252), the displayed image is erased (step #253) and the flowreturns to step #203. If the erase switch S_(E) has not been turned ON(NO in step #252), on the other hand, the flow returns directly to step#203.

The process flow subsequent to #235 is a judgment routine for theswitches 14 and 15 during shooting, i.e., when printing or reproductionis not performed. When the switch 15 is turned ON (YES in step #235),the shooting lens 3 is switched to the extreme telephoto side (step#236). If the switch 14 is turned ON (YES in step #237), on the otherhand, the shooting lens 3 is switched to the extreme wide-angle side(step #238). If each of the switches 14 and 15 is OFF, the shooting lens3 is not switched. Finally in the interrupt routine, it is judgedwhether or not the undercharge flag is “1” (step #239). If theundercharge flag is “1” (YES in step #239), an interrupt has occurredduring charging so that the CPU 100 resumes the charging operation thathas been interrupted in the undercharged state (step #240). If theundercharge flag is “0”, the charging operation is not resumed.

Thus, according to the present embodiment, the voltage judgment level isset for each of the printer unit and the camera unit. This makes itpossible to not only enable or disable the operation of each of theprinter unit and the camera unit, but also enable the operation ofeither one of the printer unit and the camera unit and disable theoperation of the other of the printer unit and the camera unit.

As a result, the minimum function can be performed even if the voltageof the power source battery is lowered.

It is to be noted that the battery includes each of a rechargeablebattery and a non-rechargeable battery.

It is to be noted that the present invention is not limited to theforegoing embodiments and can be practiced in various other embodiments.For example, the present invention is applicable, in exactly the samemanner, to a digital camera having a printing function in which theprinter unit is detachable from the camera main body.

Furthermore, the present invention is applicable, in exactly the samemanner, to a digital video camera having a printing function in whichthe moving image is recorded.

Although the present invention has been fully described by way ofexamples with reference to the accompanying drawings, it is to be notedthat various changes and modification will be apparent to those skilledin the art. Therefore, unless otherwise such changes and modificationsdepart from the scope of the present invention, they should be construedas being included therein.

The foregoing description of the preferred embodiments of the inventionhave been presented for purposes of illustration and description. Theyare not intended to be exhaustive or to limit the invention to theprecise forms disclosed, and obviously many modifications and variationsare possible in light of the above teaching. The illustrated embodimentswere chosen and described in order to best explain the principles of theinvention and its practical application to thereby enable others skilledin the art to best utilize the invention in various embodiments and withvarious modifications as are suited to the particular use contemplated.It is intended that the scope of the invention be defined by the claimsappended hereto.

What is claimed is:
 1. A digital camera having a printing function,which is driven by a battery, said digital camera comprising: a printerunit operable when a voltage of the battery is equal to or higher than afirst voltage; a camera unit operable when the voltage of the battery isequal to or higher than a second voltage; a detector for detecting thevoltage of the battery; and a controller for comparing the voltage ofthe battery, detected by the detector, with the first and secondvoltages and controlling respective operations of the printer unit andthe camera unit based on the result of the comparison.
 2. The digitalcamera of claim 1, wherein the controller performs a control operationwhereby the respective operations of the printer unit and the cameraunit are enabled or disabled based on the result of the comparison. 3.The digital camera of claim 1, wherein the second voltage is lower thanthe first voltage.
 4. The digital camera of claim 1, further comprising,a selector for selecting either a function of the printer unit or afunction of the camera unit.
 5. The digital camera of claim 4, whereinthe controller compares a voltage required for the function selected bythe selector with the voltage of the battery.
 6. The digital camera ofclaim 5, wherein the controller compares the voltage of the battery withthe first voltage when the printer unit is selected and the controllercompares the voltage of the battery with the second voltage level whenthe camera unit is selected.
 7. The digital camera of claim 6, furthercomprising an indicator for displaying the result of the controloperation performed by the controller whereby the respective operationsof the printer unit and the camera unit were enabled or disabled.
 8. Thedigital camera of claim 5, wherein the controller disables or enablesthe operation of either one of the printer unit selected or camera unitselected.
 9. The digital camera of claim 1, wherein the controllerperforms the comparing operation or the control operation insynchronization with the camera unit performing a shooting preparationoperation.
 10. The digital camera of claim 1, wherein the controllerperforms the comparing operation or the control operation when thebattery is replaced.
 11. A method of controlling a digital camera havinga printing function, which is driven by a battery, said methodcomprising the steps of: detecting a voltage of the battery; comparingthe detected voltage of battery with a first and second voltage;permitting a shooting operation and a printing operation when thedetected voltage of battery is equal to or higher than the firstvoltage; and permitting the shooting operation and prohibiting theprinting operation when the detected voltage of battery is equal to orhigher than the second voltage and when the detected voltage of batteryis lower than the first voltage.